Physical and chemical properties of PAN-derived electrospun activated carbon nanofibers and their potential for use as an adsorbent for toxic industrial chemicals

A recently developed carbon material, electrospun Activated Carbon nanoFiber (ACnF), exhibits strong potential for use as an adsorbent for toxic industrial chemicals (TICs). As-prepared ACnF contains as much as 9.6?wt% nitrogen, creating a basic surface that enhances acid-gas adsorption. ACnF shows 4–20 times greater HCN adsorption capacities and 2–5 times greater SO₂ adsorption capacities in dry nitrogen, compared to commercially available activated carbon fiber cloth (ACFC) and Calgon BPL? granular activated carbon, which are considered here as reference adsorbents. ACnF has 50?% of the micropore volume (0.30?cm³/g) of these reference adsorbents, which limits its adsorption capacity at high concentrations for volatile organic compounds (>500?ppm_v). However, at low concentrations (<500?ppm_v), ACnF has a similar capacity to ACFC and about three times the VOC adsorption capacity of Calgon BPL?. ACnF’s small fiber diameters (0.2–1.5?μm) allow for higher mass transfer coefficients, resulting in adsorption kinetics nearly twice as fast as ACFC and eight times as fast as Calgon BPL?. ACnF drawbacks include hydrophilicity and reduced structural strength. The rapid adsorption kinetics and high capacity for acidic TICs warrant further investigation of ACnF as an adsorbent in respiratory protection and indoor air quality applications.